The invention relates to a machine for the treatment of animal hides and skins, intended for use in leather and fur manufacture, as well as for their preservation. It can be used in all businesses and establishments that are engaged in the manufacture of leather and furs, as well as in the preservation of hides and skins.
A continuously-operating machine for the treatment of animal hides and skins previously known is in the form of a spiral device or spiral barrel for the manufacture of leather, as well as for their preservation. The loading takes place at the end of a tube-like continuously-operating machine, which is rotatably arranged around a horizontal axis, and the discharge takes place by automatic ejection of the hides at the opposite end. The interior walls of the continuously-operating machine have an Archimedean spiral (worm) which divides the hollow cylinder into segments. The treatment of hides and skins with chemicals preferably takes place in an aqueous medium (dye) by gyratory movements of the continuously-operating machine. With a complete turn, the hides are moved one segment in the direction of ejection and in this way ejected out when reaching the last segment (Pauligk/Hagen "Lederherstellung", VEB Fachbuchverlag 1973, p. 78; Krasnow B. Ja "Materialien fuer Erzeugnisse aus Leder", Verlag Leichtund Lebensmittelindustrie, Moskau 1981, p. 37, Russ.)
A disadvantage of this continuously-operating machine is that the dye temperature cannot be set and regulated. It is therefore not possible to carry out the treatment process at the technologically optimum temperature, which is preferably above room temperature. This leads to longer reaction times, which in turn result in higher costs of operation and disadvantageous influences on the leather quality, in the form of an increased occurrence of large grains.
Additional disadvantages relate to the loading and especially the discharge of tanning materials and adjuvant substances from the machine, which are preferably supplied to and discharged from the segments in the form of aqueous dye. Although the supply of the individual segments with various substances is principally possible by means of a corresponding number of independent conduits in the hollow axis, the larger diameters of the conduits, which are necessary for a rapid supply of dye and subsequent short reaction times, result in a considerable reduction of the effective volume of the continuously-operating machine, because of the enlargement of the hollow axis. It is particularly disadvantageous in that the dye cannot be emptied out of the segments without first stopping the machine.
An additional continuous process for the treatment of leather is known (Darmstaedter Durchlaufverfahren), in which the hides are hung over rods individually by hand (Das Leder 1980, 31 p. 68, Eduard Roether Verlag Darmstadt). This method has the disadvantage of requiring great manual effort. Furthermore, the hides have to be secured against sliding off the rods.
For the treatment processes of leather and fur manufacture, machines with rotating, perforated interior drums in a stationary sealed shell are also used. The heating of the dye occurs between the rotating drum and the stationary shell. The temperature of the dye can be regulated. Water, liquid and solid chemicals can be automatically supplied and the individual process steps automatically executed according to plan. The disadvantage of this machine is that the loading and discharge of the hides takes place through the same drum- and shell-opening. For this, the machines must be stopped and the drums retained in such a way that the openings of the drum and shell correspond with one another.
The manual removal of the hides from the machine is combined with especially hard physical work and requires considerable non-operational periods of these valuable means of production. A continuous process is not possible with these machines. An additional disadvantage of these machines is that a considerable dye volume is necessary (at least 30 to 40% of the hides to be processed). These machines are not suitable for processes without dye (DE-OS No. 26 48 057).
It is therefore the object of the invention to eliminate these disadvantages and to create a machine, which guarantees quality treatment of animal hides and furs for leather and fur manufacture and preservation in an economical way, and which shortens the process, saves chemical agents and work, reduces the waste water stress and the need for production space, saves electricity, increases the productivity and improves working conditions.
The invention has the object of creating a machine for the treatment of animal hides and skins to be used in leather and fur manufacture and preservation, which operates according to the continuous flow principle and which allows the use of the most practical technology. In order to realize the technologically optimum process, the optimal reaction temperature can be set and regulated. The treatment can take place in long, as well as in short, dyes and also in solutions without dye. The supply of dye and solid chemicals as well as separation of the dye from the hide material occur while the machine is operating and occur so quickly that short time processes are possible, which considerably shorten the processing time of hides and skins. Unused tanning material and chemical adjuvants can be recovered and reused. The machine operates automatically to a great extent.